Monument Bank said it plans to tokenise up to 250 million pounds ($335 million) of retail customer deposits on the Midnight network in what it described as the first such move by a U.K.-regulated bank on a public blockchain.

The London-based challenger bank said the deposits will remain interest-bearing, fully backed by Monument and redeemable one-for-one in pounds sterling. They will also remain covered by the U.K.’s Financial Services Compensation Scheme.

The move marks is a step in the push to bring tokenized financial products into regulated banking. While banks in the U.K. and elsewhere have explored tokenized deposits, most work to date has focused on institutional use or closed networks.

Monument is pitching this effort at retail customers, starting with clients with investable assets between 50,000 pounds and 5 million pounds, the so-called mass-affluent, according to asset manager St. James's Place.

Monument, which says it has more than 100,000 customers and about 7 billion pounds in deposits, said the first phase will mirror savings balances on Midnight’s privacy-focused blockchain.

Later phases are meant to add tokenized investment products such as private market and commodity funds, followed by lending against those holdings inside the Monument app.

Midnight Foundation, which was developed by Shielded Technologies, a company linked to Cardano creator Input Output, is providing the blockchain infrastructure.

Monument said the system is designed so transaction data remains visible only to the bank and its customers, while operating within existing U.K. banking protections and compliance rules.

The announcement also points to a wider play. Monument said affiliate Monument Technology plans to offer tokenized deposit functionality through its Banking-as-a-Service platform. That could allow other institutions to adopt the same model.